In such case $filter would need to be used in projection stage. A document looks like so:, ])Ī user review would be matched with all the replies where userReviewId equals to the _id of the user review and the replies field contains at least 1 approved reply. The returned elements are in the original order. This page provides examples of query operations on embedded/nested documents using the db.collection.find() method in the mongo shell. Returns an array with only those elements that match the condition. Each reply also has a status field which tells us whether a reply is approved or not to be displayed on the website. Selects a subset of an array to return based on the specified condition. So, ascents.total means that MongoDB should first open the nested document that the ascents field points to and then find the total field within it. Suppose we have a collection named UserReview which contains reviews users made for a certain product and the documents also have a replies field which contains an array of comments made to a review. To use MongoDB Compass, you must install it on your local computer. In nested documents, the access path to any given field is constructed with dots indicating the action of going inside the nested object. $elemMatch can be used in find operations. However, sometimes you may want to filter some field, specifically an array field by a certain condition. I am trying to perform a filter on a nested array of objects using aggregate, project, filter operators but I have not been successful yet in getting the expected output. Find Parent objects through intermediated child collection in MongoDB. How to query all children of an object within a document 0. Usually when you make queries in MongoDB, the returned result is the whole document with all the fields unless you make a projection. Querying array of nested objects in MongoDB.
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